ABSTRACT
We present the first experimental limits on high-q2 contributions to charmless semileptonic decays of the form expected from the weak annihilation (WA) decay mechanism. Such contributions could bias determinations of /Vub/ from inclusive measurements of B-->Xulupsilon. Using a wide range of models based on available theoretical input we set a limit of GammaWA/Gammab-->u<7.4% (90% confidence level) on the WA fraction, and assess the impact on previous inclusive determinations of /Vub/.
ABSTRACT
We observe signals for the decays psi(3770) --> XJ/psi from data acquired with the CLEO detector operating at the CESR e+ e- collider with square root of s = 3773 MeV. We measure the following branching fractions Beta(psi(3770) --> XJ/psi and significances: (189 +/- 20 +/- 20) x 10(-5) (11.6sigma) for X = pi+ pi-, (80 +/- 25 +/- 16) x 10(-5) (3.4sigma) for X = pi0 pi0, and (87 +/- 33 +/- 22) x 10(-5) (3.5sigma) for X = eta, where the errors are statistical and systematic, respectively. The radiative return process e+ e- --> gamma psi(2S) populates the same event sample and is used to measure Gamma ee[psi(2S)] = (2.54 +/- 0.03 +/- 0.11) keV.
ABSTRACT
We determine the dielectron widths of the Gamma(1S), Gamma(2S), and Gamma(3S) resonances with better than 2% precision by integrating the cross section of e+e- -->Gamma over the e+e- center-of-mass energy. Using e+e- energy scans of the Gamma resonances at the Cornell Electron Storage Ring and measuring Gamma production with the CLEO detector, we find dielectron widths of 1.252+/-0.004(sigma(stat))+/-0.019(sigma(syst)) keV, 0.581+/-0.004+/-0.009 keV, and 0.413+/-0.004+/-0.006 keV for the Gamma(1S), Gamma(2S), and Gamma(3S), respectively.
ABSTRACT
The h(c)((1)P(1)) state of charmonium has been observed in the reaction psi(2S) --> pi(0)h(c) --> (gammagamma)(gammaeta(c)) using 3.08 x10(6) psi(2S) decays recorded in the CLEO detector. Data have been analyzed both for the inclusive reaction, where the decay products of the eta(c) are not identified, and for exclusive reactions, in which eta(c) decays are reconstructed in seven hadronic decay channels. We find M(h(c)) = 3524.4 +/- 0.6 +/- 0.4 MeV which corresponds to a hyperfine splitting DeltaM(hf)(1P) triple-bond
ABSTRACT
We describe new measurements of the inclusive and exclusive branching fractions for psi(2S) transitions to J/psi using e(+)e(-) collision data collected with the CLEO detector operating at CESR. All branching fractions and ratios of branching fractions reported here represent either the most precise measurements to date or the first direct measurements. Indirectly and in combination with other CLEO measurements, we determine B(chi(cJ) --> gamma(J/psi)) and B[psi(2S) --> light hadrons].
ABSTRACT
Using data accumulated with the CLEO detector corresponding to an integrated luminosity of [symbol: see text] = 5.63 pb(-1) on the peak of the psi(2S) [3.08 x 10(6) psi(2S) decays] and 20.70 pb(-1) at square root of[s] = 3.67 GeV, we report first measurements of the branching fractions for the following 13 decay modes of the psi(2S): eta3pi, &eta'3pi, rhoK+K-, K+K-pi+pi-pi0, 2(K+K-), 2(K+K-)pi0, rhopp, pppi+pi-pi0, etapp, ppK+K-, lambdalambdapi+pi-, lambdapK+, and lambdapK+pi+pi-, and more precise measurements of 8 previously measured modes: 2(pi+pi-), rhopi+pi-, 2(pi+pi-)pi0, omegapi+pi-, K+K-pi+pi-, omegaK+K-, phiK+K-, and pppi+pi-. We also report new branching fraction measurements of phipi+pi- and omegapp and upper limits for etapi+pi-, etaK+K-, and phivpp. Results are compared, where possible, with the corresponding J/psi branching ratios to provide new tests of the 12% rule.
ABSTRACT
Using CLEO data collected from CESR e(+)e(-) collisions at the psi(2S) resonance and nearby continuum at sqrt[s]=3.67 GeV, we report the first significantly nonzero measurements of light vector-pseudoscalar hadron pair production (including rhopi, omegapi, rhoeta, and K(*0)K0 ) and the pi(+)pi(-)pi(0) final state, both from psi(2S) decays and direct e(+)e(-) annihilation.
ABSTRACT
From electron-positron collision data collected with the CLEO detector operating at Cornell Electron Storage Ring near sqrt[s]=10.6 GeV, improved measurements of the branching fractions for tau decays into three explicitly identified hadrons and a neutrino are presented as B(tau(-)-->pi(-)pi(+)pi(-)nu(tau))=(9.13+/-0.05+/-0.46)%, B(tau(-)-->K-pi(+)pi(-)nu(tau))=(3.84+/-0.14+/-0.38) x 10(-3), B(tau(-)-->K-K+pi(-)nu(tau))=(1.55+/-0.06+/-0.09) x 10(-3), and B(tau(-)-->K-K+K-nu(tau))<3.7 x 10(-5) at 90% C.L., where the uncertainties are statistical and systematic, respectively.
